1. Field of the Invention
The present invention relates to a medical three-dimensional locating apparatus and, more particularly, to a medical three-dimensional locating apparatus for encephalic surgical operation.
2. Description of the Prior Art
The diffusion of CT scanning apparatus and MRI scanning apparatus has revolutionized encephalic nerve surgery, and three-dimensional imaging diagnosis for encephalic nerve-surgical operation has replaced conventional imaging diagnosis employing simple cranial photography or cerebral angiography.
Imaging diagnosis employing a CT scanning apparatus or a MRI scanning apparatus, however, is able only to determine the position of a focus, i.e., a target, three-dimensionally and is unable to reproduce the position data obtained by imaging diagnosis in the patient's head. Although various kinds of CT-type localization encephalic surgical apparatus are being developed currently for the reproduction of an optional point in a picture obtained by CT scanning in the patient's head, the accuracy of such apparatus is not necessarily satisfactory.
Even if the accuracy of reproduction of CT locating encephalic surgical apparatus being developed is satisfactory, still another problem, specific to an encephalic surgical operation requiring craniotomy, remains unsolved. That is, in craniotomy, surgical opening of a portion of the patient's skull corresponding to the focus is not feasible even if the position of the portion corresponding to the focus is determined and the position of the portion is nearest to the focus. This case arises particularly when important nervous tissues exist between the rear-focus portion of the patient's skull and the focus. In such a case, another portion of the patient's skull which will allow craniotomy without interfering with the particularly important nervous tissues, must be opened to approach the focus even if the position of this portion is remote from the focus. Conventional CT-type localization encephalic surgical apparatus thus requires a difficult operation to approach the focus from the remote position on the patient's skull and to find the position of an optimum portion for craniotomy.
Accordingly, it is an object of the present invention to provide a medical three-dimensional locating apparatus capable of accurately reproducing three-dimensional position data representing the position of the focus in the patient's head, obtained by CT scanning or MRI scanning in actually carrying out a surgical operation, and requiring a simple operation for finding the position of an optimum portion for craniotomy.